It is known to equip automated vehicles with a wide variety of sensing systems. Various sensor configurations have been developed to provide assistance or information to a driver or autonomous controller regarding the environment surrounding the vehicle. Advances in radio frequency signaling technology have enabled the development of sophisticated system-on-a-chip integrated circuits. The functionality required for environmental sensing or communications can be embodied in integrated circuit components. Example uses for such devices include automotive vehicle radar detection systems, robotics guiding systems, and Wi-Fi data transfer.
Antennas for radio-frequency (RF) signal transmission vary depending on the particular sensing or communication of interest. For example, relatively small, low-gain, broadband antennas are used for Wi-Fi communications, and relatively large, high-gain antennas are typically used for point-to-point data communications. Antennas useful for automotive radar systems typically fall between those two extremes. One type of antenna component that can be useful for propagating RF signals in a vehicle-based radar system is known as a substrate-integrated-waveguide (SIW). The SIW is desirable because of high-efficiency and are relatively low-cost.
One challenge associated with utilizing SIWs in a vehicle-based sensing or communication system is associated with the connection between an integrated circuit and the SIW. For example, microstrip or coplanar waveguide microwave transmission lines can provide an interface between the integrated circuit and the SIW. However, such connections include drawbacks, such as the requirement for a microwave component that matches the field configuration peculiar to each transmission line. The transition associated with such a microwave component increases microwave loss and introduces microwave reflections that may limit bandwidth and impact the ability to produce such systems. When a microstrip is used, bandwidth may be limited by the requirement for the ground connection to pass from the integrated circuit component connectors through the SIW substrate to a metal layer on that substrate. Furthermore, such connections are typically made using a relatively expensive blind via process.